The Virginia senator, chosen Friday to be Hillary Clinton’s running mate, will take the stage at the Democratic National Convention in Philadelphia, where party leaders are hoping to send a message of unity — and highlight stark divisions in the Republican Party intensified by Donald Trump — on the tails of a boisterous GOP gathering in Cleveland.

Kaine, for those purposes, is something of a gamble.

The moderate Democrat has backed abortion restrictions; supported fast-track authority for a controversial Pacific Rim trade deal; and just last week joined a push to deregulate some of the nation’s largest banks — all positions that are anathema to the liberals being wooed by the Clinton team heading into November.

Raising the stakes, the convention marks the end of a bruising Democratic primary contest between Clinton and Sen. Bernie Sanders (I-Vt.) in which Sanders’s liberal supporters continuously bashed the former secretary of State for being too conservative on some of those same issues, including trade and her ties to Wall Street.

Clinton, now the presumptive nominee, has shifted left in an effort to appease those critics — with help from a recent Sanders endorsement — but in a challenge to Democrats’ unity push, throngs of protesters are expected in Philadelphia this week.

Those liberal voices, seen as vital to Clinton’s election chances, had pressed her to choose a more left-leaning vice presidential candidate — someone in the mold of Sens. Sherrod Brown(D-Ohio), Elizabeth Warren (D-Mass.) or Jeff Merkley (D-Ore.) — and it’s unclear how the more centrist Kaine will be received.

Leading up to the pick, there was a great deal of speculation that Clinton would choose either a minority or female candidate in order to maximize turnout among large blocs of voters already alienated by Trump. That list included Sen. Cory Booker (D-N.J.), Rep. Xavier Becerra (D-Calif.), Labor Secretary Thomas Perez and Julián Castro, President Obama’s housing chief.

Following the recent terrorist attack in Nice, France, mass shootings in Texas, Florida and Louisiana, and the killing of two black men at the hands of police in Minnesota and Louisiana, the nation has grown jittery over security concerns. Trump has responded by focusing his campaign on a theme of “law and order,” and Clinton faced pressure to counter the message.

Kaine fits the bill. The former Virginia governor serves on both the Armed Services and Foreign Relations committees, where he’s focused intently on anti-terror measures and led the push for Congress to approve a new authorization for military force specific to the fight against the Islamic State in Iraq and Syria.

Sen. Angus King, an Independent Maine lawmaker who caucuses with Democrats, recently noted that experience as just one of many reasons Kaine is perfectly suited for the vice presidency.